This invention relates to a printer which performs printing based on image information obtained from an information processing apparatus and a control method for the printer and, more particularly to a printer, to which an optional device can be attached, and a control method for the printer.
Recently, a printer, which has a simplified construction and which performs various operations by control of software programs which run on a host computer, has been put into practical use as a so-called host-base printer. In this system, various printer operations are controlled via a printer driver in the host computer, by bidirectional communication between the printer and the host computer.
Upon starting print operation, the printer driver installed in the host computer determines whether or not it supports the printer connected to the host computer. In this system, to attach an optional device to the printer, it is necessary that the printer driver has the capability to communicate with the optional device. For example, if an optional device of the printer is a postcard feeder, the capability of the printer driver must include the card feeder function.
Accordingly, in a case where a new optional function not supported by the printer driver is employed, a revised printer driver is included in a package upon shipment. When the new optional function is installed, the previous printer driver is replaced by the revised printer driver.
However, the above conventional technique has the following problem.
Conventionally, the host computer uses one device ID to recognize the printer regardless of option-device setting status (i.e., attached or not) of the printer. More specifically, the host computer recognizes a printer having a newly-attached optional device with the same ID as that used to recognize the printer before the optional device is attached to the printer. Accordingly, the host computer cannot detect whether or not the optional device has been attached to the printer. If a printer, to which an optional function is attached, is connected to the host computer but the host computer system is not updated to include the new function, the printer might perform erroneous operation. Similarly, when a printer, to which no optional device is attached, is connected to the host computer but the host computer system has been updated to include the new function of the printer driver, the printer might perform erroneous operation.